Why does dusty weather generally appear in the south?

The first is the geographical location of the north, which is the basis of windy and dusty spring in the north. As can be seen from the map, the northwest, north and northeast of China are very close to the desert. Among them, the northwest itself has a large desert Gobi, including Taklimakan Desert, Mu Us Desert and Badain Jaran Desert. In addition to the Gobi desert centered on Lop Nur; North China is not far from the desert in Inner Mongolia, and there is a large Gobi in the Mongolian Plateau in the north. To the west of the northeast, opposite the Daxinganling Mountains is also a large Gobi. These Gobi Desert are sand sources and inexhaustible dust sources. The north is next to them, and naturally there will be sandstorms.

There are large areas of Gobi Desert in northern China and Mongolian Plateau, which are sand sources.

Secondly, why is it windy and dusty in spring? Why not in winter and autumn? This is because the Gobi desert freezes in winter, and a little water on the surface of the Gobi desert becomes "glue". If the dust is fixed, it will be difficult for the wind to blow. In autumn, the Gobi desert has just passed a short rainy season or rainy season, and there is still some moisture, so the sand is not easily blown by the north wind. Only in spring, after the Gobi desert thaws, there is little rain, and dust is easily blown up. As long as there is a north wind, dusty weather will form in the south. Of course, in some years, there is more precipitation in spring and less dust, which is also the same reason.

Third, why is the north wind so strong in spring? Because first of all, China is a country with monsoon climate. When the summer monsoon in spring hasn't come and the winter monsoon hasn't subsided, the cold air often goes south, and the north wind blows as soon as the cold air goes south; Secondly, we also mentioned in the previous answer that when the cold air moves south in spring, the temperature on the land in China is already very high, and cyclones and thermal depressions often develop, which will increase the pressure gradient; There is no such factor when the cold air goes south in winter. So the cold air and strong wind in spring are sometimes bigger than in winter. With sand, sand can blow up, and there is a north wind. It is not surprising that there is dust in the north in spring.